The Removal Of Pollutants From Water By Bisphenol A Molecular Imprinted Adsorbent

For improving the adsorption capacity and selectivity of Bisphenol （BPA）, molecularlyimprinted adsorbent for bisphenol A （BPA–MIA） is prepared using the surface molecularimprinting technique with a sol–gel process on the surface of silica nanoparticles. The BPAwas using as template, silica was using as support, diethylenetriaminepentaacetic acid （DTPA）was using as a functional monomer and teraethyl orthosilicate （TEOS） was using as across–linker. The dosages of DTPA and TEOS were optimized, respectively. The preparedBPA–MIA was characterized by SEM, EDS, FTIR, TG and BET analysis. Proposed theaverage imprinting point at the surface of adsorbent （c） was a measure of molecularlyimprinted adsorbent for the first time with Scatchard function.Moreover, the proper binding and selective recognition ability of BPA–MIA andBPA–NMIA were also investigated by a single batch binding experiment, such as the addition,the adsorption dynamics, the adsorption isotherm, the adsorption thermodynamics and thereuse ability. The interference tests of BPA–MIA were proposed to illustrate the adsorptionstability of BPA–MIA for BPA in real water samples. The influences of single and hybridsystems were investigated by using phenolic compound. And the mechanisms of adsorptionwere analyzed.With the dosages of DTPA and TEOS improving, the characterized analysis showed themicrostructurs of BPA–MIA have changed, the total weightlessness and the characteristicgroups of DTPA increased gradually. The removal of BPA achieved maximum. The averageparticle size of BPA–MIA was450nm, BPA–MIA was composed by elements Carbon,Oxygen and Silicon. The specific surface area of BPA–MIA was1.7times of BPA–NMIA.The Q_mof Scatchard function was31.44μmol·g^-1after line fitting, and c was0.181μmol·m^-2.The results showed the equilibrium data fitted well to the pseudo–second–order kineticand the Langmuir model for BPA binding onto BPA–MIA and BPA–NMIA, respectively. Theinitial adsorption rate of BPA–MIA and BPA–NMIA were1.49μmol·g^-1·min^-1and1.85μmol·g^-1·min–1, respectively. The saturate binding capacity of BPA–MIA was found to be30.26μmol·g^-1, which was three times higher than that of BPA–NMIA. The adsorptivereactions of BPA–MIA and BPA–NMIA were spontaneously endothermic reaction, and the structures of BPA–MIA and BPA–NMIA could be changed under binding BPA. Besides,BPA–MIA can be used repeatedly for five ten times with5.7%loss of adsorption capacity.The interference tests were proved that the interfering materials had no effect on bindingBPA. Moreover, BPA–MIA could be applied in actual water samples. TBBPA and BPA couldbe selectively adsorbed by BPA–MIA. The selective adsorption of BPA–MIA was influencedby molecular structures and chemical properties. These results demonstrate that BPA–MIApossessed a vast range of application prospect in concentrated or adsorbed BPA from rawwater.Based on the above, BPA–MIA showed an appreciable binding specificity towards BPAthan similar structurally compounds in water phase. The BPA–MIA could serve as anefficient selective material for determining or removing BPA from water environment.